# Personal Engineering Platform > Shared, dated engineering defaults for personal projects - HTML version: https://robbiepalmer.me/projects/personal-engineering-platform - Status: live - Started: 2026-09-12 - Technologies: TypeScript, Python, Zod, Pydantic, pytest-cases, Cloudflare Workers, Terraform, PostHog, Netdata, PostgreSQL, Neon, DuckDB # Purpose The Personal Engineering Platform owns reusable engineering policy. Projects opt into named layers and keep their own decision histories for product choices and deliberate overrides. The manifest below the project introduction is the source of truth for current defaults. Every policy and selection has an effective period and a deciding ADR, so historical project stacks do not change when the platform does. # Scope The platform records choices that apply across projects: repository and CI defaults, language tooling, application runtimes, infrastructure, telemetry, and data stores. It does not own product architecture or employer policy. Required slots apply to every project that uses their layer. Preferred slots apply only after a project records that it needs the capability. ## Current layer manifest ### Base Repository, task-running, CI, and common security defaults. - project.primary-language: required ### TypeScript Defaults for projects whose primary language is TypeScript. Activated when project.primary-language resolves to typescript. - typescript.schema-validation: required ### Python Defaults for projects whose primary language is Python. Activated when project.primary-language resolves to python. - python.data-validation: required - python.test-cases: required ### Web application Defaults for browser-delivered applications. ### Backend API Defaults for network APIs and server-side application code. - backend-api.runtime: preferred ### Infrastructure Defaults for provisioning and infrastructure management. - infrastructure.provisioner: preferred ### Observability Defaults for application telemetry and node monitoring. - observability.application-telemetry: preferred - observability.node-monitoring: preferred ### Database Conditional defaults for transactional and analytical data. - database.relational-engine: preferred - database.relational-host: preferred - database.olap-engine: preferred ## Default history ### Primary language The language that determines the project's language-tooling layer. - [typescript](https://robbiepalmer.me/technologies/typescript.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/001-language-defaults.md); driven by [personal-site](https://robbiepalmer.me/projects/personal-site.md) - Users: [agent-first-writing](https://robbiepalmer.me/projects/agent-first-writing.md), [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [personal-site](https://robbiepalmer.me/projects/personal-site.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) - Overrides: [agent-first-writing:009-primary-language-python](https://robbiepalmer.me/projects/agent-first-writing/adrs/009-primary-language-python.md) ### TypeScript schema validation Runtime validation at TypeScript data boundaries. - [zod](https://robbiepalmer.me/technologies/zod.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/001-language-defaults.md); driven by [personal-site](https://robbiepalmer.me/projects/personal-site.md) ### Python data validation Typed validation for Python inputs and configuration. - [pydantic](https://robbiepalmer.me/technologies/pydantic.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/001-language-defaults.md); driven by [agent-first-writing](https://robbiepalmer.me/projects/agent-first-writing.md) ### Python test cases Reusable and parameterised Python test cases. - [pytest-cases](https://robbiepalmer.me/technologies/pytest-cases.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/001-language-defaults.md); driven by [agent-first-writing](https://robbiepalmer.me/projects/agent-first-writing.md) ### Backend API runtime The managed runtime for an HTTP API. - [cloudflare-workers](https://robbiepalmer.me/technologies/cloudflare-workers.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/002-cloudflare-workers.md); driven by [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) - Users: [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) ### Infrastructure provisioner Declarative provisioning for managed infrastructure. - [terraform](https://robbiepalmer.me/technologies/terraform.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/003-terraform.md); driven by [personal-site](https://robbiepalmer.me/projects/personal-site.md) - Users: [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [personal-site](https://robbiepalmer.me/projects/personal-site.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) ### Application telemetry Product analytics, traces, logs, and application-level signals. - [posthog](https://robbiepalmer.me/technologies/posthog.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/004-observability.md); driven by [personal-site](https://robbiepalmer.me/projects/personal-site.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) - Users: [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [personal-site](https://robbiepalmer.me/projects/personal-site.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) ### Node monitoring Host and node health metrics for operated machines. - [netdata](https://robbiepalmer.me/technologies/netdata.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/004-observability.md); driven by [homelab](https://robbiepalmer.me/projects/homelab.md) - Users: [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [personal-site](https://robbiepalmer.me/projects/personal-site.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) ### Relational database engine Transactional relational storage when a project needs it. - [postgresql](https://robbiepalmer.me/technologies/postgresql.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/005-database-defaults.md); driven by [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) - Users: [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) ### Managed relational host A managed host for the selected relational engine. - [neon](https://robbiepalmer.me/technologies/neon.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/005-database-defaults.md); driven by [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) - Users: [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) ### OLAP engine Analytical SQL processing when a project needs it. - [duckdb](https://robbiepalmer.me/technologies/duckdb.md): Accepted, 2026-09-12T00:00:00Z to present; [decision](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/005-database-defaults.md); driven by [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md) - Users: [agentic-code-review](https://robbiepalmer.me/projects/agentic-code-review.md), [recipe-site](https://robbiepalmer.me/projects/recipe-site.md) ## Initiatives - [Semi-autonomous Software Development](https://robbiepalmer.me/initiatives/semi-autonomous-software-development.md): A connected system that keeps useful work moving, asks for human judgment when it matters, and learns how to need less intervention next time ## Architecture Decision Records - [ADR 000: Temporal platform layers](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/000-temporal-platform-layers.md) — Accepted, 2026-09-12 - [ADR 001: TypeScript and Python language defaults](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/001-language-defaults.md) — Accepted, 2026-09-12 - [ADR 002: Cloudflare Workers for backend APIs](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/002-cloudflare-workers.md) — Accepted, 2026-09-12 - [ADR 003: Terraform for infrastructure provisioning](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/003-terraform.md) — Accepted, 2026-09-12 - [ADR 004: Separate application telemetry from node monitoring](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/004-observability.md) — Accepted, 2026-09-12 - [ADR 005: Capability-specific database defaults](https://robbiepalmer.me/projects/personal-engineering-platform/adrs/005-database-defaults.md) — Accepted, 2026-09-12 --- Markdown index of this site: https://robbiepalmer.me/llms.txt