PK

Timeline

Posts by month and year

Browse the archive chronologically, with counts grouped by year and month.

125 Total dated posts

2026

53 posts

May 2026

23 posts
  1. May 22 Agentic Systems Are Distributed Systems With an Unreliable Planner Agentic Systems A 33-part engineering series on distributed systems, agentic systems, harness engineering, and production harness agents.
  2. May 21 Ambiguous Outcomes Are the Core Distributed Systems Problem Agentic Systems The hard state in distributed systems is not failure, but not knowing whether the effect already happened.
  3. May 20 Idempotency Is Durable Intent Agentic Systems Idempotency works when it preserves a decision across retries, crashes, and uncertain outcomes.
  4. May 19 Reconciliation Is Where Correctness Becomes Real Agentic Systems A system is not correct because it accepted a command; it becomes correct when it can compare intent with reality and repair the gap.
  5. May 18 What I Wish More Engineers Understood About Power Life A clear-eyed model of power, trust, incentives, and responsibility in engineering organizations.
  6. May 18 Leases, Ownership, and Fencing Agentic Systems A lease only says who probably owns work right now; fencing is what stops stale owners from writing after they lose it.
  7. May 17 Backpressure Is a Product Boundary Agentic Systems Backpressure is where a system tells the truth about what it can accept, delay, prioritize, or refuse.
  8. May 16 Queues Are Not Reliability Agentic Systems A queue can preserve work and decouple timing, but it does not make processing correct by itself.
  9. May 15 Deadlines Beat Timeouts Agentic Systems Timeouts protect individual calls; deadlines protect the whole promise the system made.
  10. May 14 Replay Changes Everything Agentic Systems Replay turns production failures from arguments about logs into experiments against recorded inputs, decisions, and effects.
  11. May 13 Sagas Without Fantasy Rollbacks Agentic Systems A serious saga design treats compensation as forward recovery, not a pretend undo button.
  12. May 12 Control Plane vs Data Plane Failures Agentic Systems Separating control plane and data plane behavior keeps management failures from casually breaking committed work.
  13. May 11 Agents Are Unreliable Planners Attached to Real Tools Agentic Systems A production frame for treating agent plans as tentative while tool effects stay real.
  14. May 10 Tools Are Capabilities, Not Functions Agentic Systems A practical model for designing agent tools around authority, scope, and side effects.
  15. May 9 The Agent Action Lifecycle Agentic Systems A concrete lifecycle for turning uncertain agent intent into bounded, verified effects.
  16. May 8 Context Provenance Matters More Than Prompting Agentic Systems Why agent reliability depends on knowing where context came from, when it was captured, and what it is allowed to justify.
  17. May 7 Agent State Should Live Outside the Model Agentic Systems A practical argument for storing task state, approvals, actions, and verification outside the conversation window.
  18. May 6 Stop Conditions Are Safety Features Agentic Systems How explicit stop conditions keep agent systems from turning uncertainty into expanding side effects.
  19. May 5 Agents Need Read/Write Separation Agentic Systems Why useful agent autonomy starts by separating observation from mutation.
  20. May 4 Human Approval Is a Protocol Agentic Systems How to make human approval precise enough to govern agent actions instead of decorating them.
  21. May 3 Agent Observability Should Follow Decisions, Not Tokens Agentic Systems A decision-centered observability model for debugging agent behavior after real side effects.
  22. May 2 Why I Write Before I Decide Life How writing turns vague opinions into inspectable engineering decisions.
  23. May 1 The Model Should Not Be the Policy Engine Agentic Systems Why agent systems should keep policy enforcement outside the model even when the model helps interpret intent.

April 2026

16 posts
  1. April 30 A Harness Is a Controlled World Agentic Systems Agent harnesses earn trust by controlling the world around the model, not by asking the model to explain itself.
  2. April 29 Grade State, Not Speech Agentic Systems Agent quality should be judged by the state it leaves behind, because fluent explanations can hide unsafe actions.
  3. April 28 Replay Is the Difference Between Debugging and Guessing Agentic Systems Replay turns failed agent runs into inspectable infrastructure events instead of arguments about prompts.
  4. April 27 Test the Refusal Path Agentic Systems Safe agent systems need tested refusal paths, because declining action is a production behavior with side effects.
  5. April 26 Failure Injection for Agents Agentic Systems Agent harnesses should inject ordinary tool and state failures so teams can verify behavior before production does it for them.
  6. April 25 Regression Suites Should Be Built From Bad Runs Agentic Systems The most valuable agent regression cases come from real failures converted into replayable behavior contracts.
  7. April 24 Golden Behaviors Beat Golden Text Agentic Systems Agent tests should preserve required behavior instead of freezing exact prose that can pass while actions regress.
  8. April 23 Harnesses Must Catch Overreach Agentic Systems Agent harnesses need explicit overreach checks because the most dangerous failures often look like extra helpfulness.
  9. April 22 Watcher Agents Agentic Systems Watcher agents are read-only harness components that notice unsafe drift and propose interventions without taking ownership of the work.
  10. April 21 Adversary Agents Agentic Systems Adversary agents should create hostile fixtures and boundary tests, not become theatrical opponents in production workflows.
  11. April 20 Auditor Agents Agentic Systems Auditor agents review decision traces against policy and state, producing evidence-backed findings instead of vague confidence.
  12. April 19 Replay Agents Agentic Systems Replay agents reconstruct failed runs from durable traces so engineers can debug causes instead of arguing from summaries.
  13. April 18 The Career Value of Being Easy to Reason About Life Why reliability, clarity, and low-surprise behavior compound into senior leadership trust.
  14. April 18 Blast-Radius Agents Agentic Systems Blast-radius agents decompose risky agent work into reviewable units without deciding the organization's appetite for risk.
  15. April 11 Ambition Needs a Control Plane Life How to keep ambition useful by adding constraints, feedback, and explicit tradeoffs.
  16. April 4 Burnout Is a Throughput Bug Life A systems model for burnout that treats recovery as capacity planning, not weakness.

March 2026

5 posts
  1. March 31 Observability Pillars Engineering Notes from Parin's archive.
  2. March 28 The Personal Operating System of a Principal Engineer Life A practical operating model for attention, energy, writing, relationships, and technical leverage.
  3. March 21 How to Build Taste as an Engineer Life How engineers develop judgment by studying consequences, constraints, and user pain.
  4. March 14 The Case for Boring AI Infrastructure Engineering Why queues, caches, eval stores, audit logs, and boring controls beat magic in production AI.
  5. March 7 Latency, Tokens, and Trust in AI UX Engineering Why AI user experience depends on cost, waiting, uncertainty, and visible recovery paths.

February 2026

4 posts
  1. February 28 The Cost Model Every AI Product Needs Projects & Notes A unit-economics lens for token cost, latency, quality, and human review in AI products.
  2. February 21 Why Data Quality Problems Look Like Engineering Problems Engineering A taxonomy for separating data truth, pipeline behavior, model symptoms, and product expectations.
  3. February 14 Feedback Loops Beat Model Launches Engineering How feedback design determines whether AI systems improve, stagnate, or quietly drift.
  4. February 7 The ML Model Is Rarely the System Boundary Engineering A systems view of model behavior, data pipelines, fallbacks, product semantics, and human review.

January 2026

5 posts
  1. January 31 Evaluation Is the Product in AI Systems Engineering Why durable AI products are built around eval loops, not model launch announcements.
  2. January 24 AI Code Review Needs a Threat Model Engineering How to review machine-generated changes for subtle correctness, security, and maintainability risks.
  3. January 17 The Agent Loop I Trust for Production Code Projects & Notes A practical loop for using coding agents without outsourcing engineering judgment.
  4. January 10 Prompting Is Not the Hard Part of Agentic Development Engineering Why context design, verification, decomposition, and ownership matter more than clever prompts.
  5. January 3 Why AI Agents Need Smaller Interfaces Than Humans Engineering How narrow tools, explicit contracts, and small write scopes make agents safer and more useful.

2025

51 posts

December 2025

5 posts
  1. December 27 The New Skill Is Reviewing Machine Work Engineering A review rubric for AI-generated code that focuses on intent, contracts, failure modes, and tests.
  2. December 20 Agentic Coding Changes the Bottleneck, Not the Responsibility Engineering Why AI-assisted development moves senior responsibility toward framing, review, and integration.
  3. December 13 When Speed Becomes a Culture Smell Engineering The difference between healthy urgency and speed used to hide poor choices.
  4. December 12 DDD Engineering Notes from Parin's archive.
  5. December 6 The Founder-Friendly Engineer Is Not a Yes-Man Engineering How to support founder urgency while protecting the system from avoidable damage.

November 2025

5 posts
  1. November 29 Hiring for Ownership When the System Is Still Moving Engineering Signals for hiring engineers who can own ambiguous systems without needing stable ground.
  2. November 22 The First 90 Days After a Technical Pivot Engineering How to reset architecture, morale, and delivery after the product direction moves.
  3. November 15 Startup Engineering Is the Art of Choosing Which Fires Stay Lit Engineering A startup operating model for separating existential fires from noisy but survivable ones.
  4. November 8 Why Senior Engineers Should Read P&L Statements Projects & Notes How revenue, margin, cost, and risk make technical prioritization sharper.
  5. November 1 Promotion Packets Are Written One Decision at a Time Engineering How principal-level evidence accumulates through durable decisions, not last-minute brag documents.

October 2025

4 posts
  1. October 25 The Dangerous Comfort of Being the Smartest Person in the Room Life Why senior engineers must trade cleverness for systems that make other people sharper.
  2. October 18 How to Make Executives Trust Engineering Judgment Engineering A communication model for translating engineering risk into business choices without theater.
  3. October 11 Influence Is Built Before the Meeting Engineering Why senior influence comes from pre-wiring context, risks, and tradeoffs before rooms fill up.
  4. October 4 The Quiet Power of Writing the Decision Record Projects & Notes How lightweight decision records create memory, alignment, and better reversibility.

September 2025

4 posts
  1. September 27 The Architecture Review That Actually Works Engineering A review format that tests assumptions, failure modes, and operating ownership instead of style.
  2. September 20 How to Disagree With a Staff Engineer Without Making It Political Engineering A conflict model for keeping senior technical disagreement attached to evidence and risk.
  3. September 13 A Principal Engineer's Guide to Saying No Engineering How to refuse unsafe work while preserving momentum, trust, and options.
  4. September 6 Technical Debt Is Often Unpriced Strategy Debt Engineering A sharper way to discuss debt when the real issue is changing strategy, incentives, or ownership.

August 2025

5 posts
  1. August 30 Why Platform Teams Accidentally Become Gatekeepers Engineering How internal platforms drift from leverage engines into approval queues, and how to pull them back.
  2. August 23 The Best API Design Happens Before the API Exists Engineering A review method for designing APIs from lifecycle, failure, and ownership before endpoint shape.
  3. August 16 Backward Compatibility Is an Organizational Skill Engineering How compatibility survives when teams plan contracts, migrations, and deprecation paths together.
  4. August 9 Feature Flags Are Distributed Systems in Disguise Engineering The hidden consistency, cleanup, and ownership risks inside flag-driven delivery.
  5. August 2 The Difference Between Latency Budgets and Latency Wishes Engineering A practical model for converting performance goals into owned budgets across a request path.

July 2025

4 posts
  1. July 26 Observability Without Ownership Is Expensive Decoration Engineering Why dashboards only become useful when somebody owns the question they are supposed to answer.
  2. July 19 Incident Reviews Should Change Roadmaps, Not Just Runbooks Engineering How to make incident reviews produce prioritization changes instead of better-formatted regret.
  3. July 12 The Reliability Work Nobody Wants to Fund Engineering A framing for turning invisible reliability labor into risk reduction leaders can evaluate.
  4. July 5 Idempotency Is a Product Requirement Engineering Why safe retries depend on product semantics, user-visible effects, and organizational ownership.

June 2025

5 posts
  1. June 28 The Queue Is Not the Architecture Engineering How to reason about async workflows by ownership, ordering, failure semantics, and reconciliation.
  2. June 27 Unit economics Projects & Notes Business metrics for engineers who want their technical decisions to connect to the P&L.
  3. June 21 Good Distributed Systems Are Designed Around Boredom Engineering Why predictable recovery paths matter more than clever steady-state architecture.
  4. June 14 The Hidden Cost of Just One More Service Engineering A principal-engineer checklist for deciding when a service boundary is worth its operational tax.
  5. June 7 Why Most Migrations Fail Before Code Starts Engineering The migration risks that show up in ownership, sequencing, and rollback design long before implementation.

May 2025

2 posts
  1. May 31 Architecture Is Mostly Deciding What Must Not Change Engineering A practical way to separate durable constraints from implementation details before design hardens.
  2. May 24 The Principal Engineer's Real Job Is Reducing Ambiguity Engineering A field guide to turning vague technical anxiety into decisions, owners, and reversible next steps.

April 2025

4 posts
  1. April 26 The Second Half of Your Engineering Career Life How to design a long technical career around energy, renewal, craft, and changing forms of ambition.
  2. April 19 The Power of Saying I Do Not Know Engineering Why useful uncertainty from senior engineers creates better discovery, trust, and technical decisions.
  3. April 12 The Loneliness of Technical Leadership Life A grounded model for carrying senior engineering responsibility without turning isolation into distance.
  4. April 5 How to Know When to Leave Life A stay-or-leave decision frame for separating durable career signals from frustrating but temporary noise.

March 2025

5 posts
  1. March 29 The Plateau After Principal Life How growth changes when title-chasing stops working and craft, judgment, and renewal matter more.
  2. March 22 What Your Code Review Process Actually Measures Engineering An honest audit of code review incentives, reviewer stamina, design risk, and the evidence reviews miss.
  3. March 15 The Last Responsible Moment Projects & Notes A practical way to delay decisions only while the delay is still buying useful information.
  4. March 8 Configuration Is a Programming Language Engineering How configuration grows into untyped logic, and how to make it explicit, versioned, and auditable.
  5. March 1 The Testing Pyramid Is a Lie Engineering A risk-weighted testing model that invests in the regressions most worth preventing.

February 2025

4 posts
  1. February 22 Give the ORM a Boundary, Not Authority Engineering A boundary model for using ORMs where they help without letting them own domain behavior.
  2. February 15 Premature Abstraction Is Worse Than Premature Optimization Engineering Why abstractions created before the pattern is real become slower to remove than inefficient code.
  3. February 8 The Cost of Optionality in Software Design Engineering Why every preserved option taxes future changes, and how to decide when commitment is cheaper.
  4. February 1 Leaky Abstractions Are Fine Engineering A failure-mode test for deciding whether an abstraction leaks predictably enough to be useful.

January 2025

4 posts
  1. January 25 The Paradox of Experience Life How experience accelerates pattern recognition while quietly narrowing the alternatives engineers consider.
  2. January 18 How to Think in Tradeoffs Projects & Notes A decision-journal model for making engineering tradeoffs explicit, reviewable, and easier to communicate.
  3. January 11 The Reading Stack of a Principal Engineer Life A reading system for building technical judgment through systems, organizations, writing, and human behavior.
  4. January 4 What Senior Engineers Misunderstand About Junior Engineers Engineering Why junior engineers often need context, constraints, and permission more than another technical answer.

2024

21 posts

December 2024

4 posts
  1. December 28 The Minimum Viable Process Engineering How to add only the process that prevents known failure modes instead of slowing every future change.
  2. December 21 The Art of the Technical Pre-Mortem Projects & Notes A practical pre-mortem format for finding failure modes before design confidence becomes expensive.
  3. December 14 Why Good Engineers Write Bad Code Under Pressure Engineering A cognitive-load model for protecting design quality when deadlines compress attention and options.
  4. December 7 Meetings Are a Decision Latency Tax Engineering A decision-cost model for choosing when meetings help, when they stall, and what artifact should replace them.

November 2024

5 posts
  1. November 30 The Bus Factor Is a Design Constraint Engineering How to reduce knowledge concentration through architecture, operations, and ownership design instead of documentation guilt.
  2. November 23 Design Docs Are Coordination Tools Engineering Why the real value of a design doc is shared assumptions, explicit tradeoffs, and a durable decision path.
  3. November 16 Why Your RAG Pipeline Returns Garbage Engineering A failure-isolation model for debugging retrieval, ranking, context, prompt, and model behavior separately.
  4. November 9 The Latency Tail of LLM Inference Engineering Why AI latency tails behave differently and how to design product flows around token-driven variance.
  5. November 2 What Your SLA Actually Promises Engineering How to design service promises around failure shape, measurement, ownership, and who bears the cost.

October 2024

7 posts
  1. October 26 Reliability Has a Balance Sheet Projects & Notes A debit-and-credit model for pricing reliability decisions before they become invisible debt.
  2. October 19 More Replicas Do Not Mean More Reliable Engineering When replication buys resilience, when it amplifies failure, and what to check before adding another copy.
  3. October 14 Parin's reflections -- A (fictional) story about myself Life A fictionalized self-portrait about ambition, pause, spirituality, and finding a richer melody.
  4. October 12 Your System Is Already Partitioned Engineering A practical taxonomy of everyday micro-partitions and the design habits that make them survivable.
  5. October 5 Why Fail Fast Falls Apart in Money-Moving Systems Engineering Why financial workflows need cautious failure semantics, reconciliation, and slower decisions than ordinary services.
  6. October 2 Java DS Summary Engineering A practical Java data-structures refresher for interview prep and daily problem solving.
  7. October 1 The (Web) Reading Ruler Projects & Notes A browser userscript for saving and restoring a custom reading ruler across pages.

September 2024

5 posts
  1. September 28 System Design Engineering Scalability, load balancing, sharding, caching, and other system design fundamentals.
  2. September 27 Leet code patterns with problems Engineering LeetCode patterns paired with representative problems and descriptions.
  3. September 27 Leet code patterns summary Engineering A compressed map of interview problem patterns: windows, pointers, graphs, dynamic programming, and more.
  4. September 23 Om Life A quiet opening prayer to mark the beginning of the blog.
  5. September 23 From Hustle to Heal: Why I Quit My High-Paying Job to Take a Break and Reclaim My Life Life A candid, funny, deeply Indian essay about quitting a high-paying job to recover health and meaning.