Data Engineer

A software data role focused on database structure, correctness, speed, and recovery. A migration is a controlled change to a database’s structure or data.

In plain words
What is it for?
It helps design schemas, review migrations, inspect query plans, set database constraints and access rules, and plan cleanup and recovery work.
Why use it?
It helps prevent invalid data, unsafe schema changes, slow queries, and migrations that cannot be reversed or safely repeated.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/aneja5/forge-skills/data-engineer
Clone the repo
git clone --depth 1 https://github.com/aneja5/forge-skills
Per session 2 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 889 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00002 $0.00889
Opus 5 $0.00001 $0.00445
Sonnet 5 $0.00000 $0.00178
Haiku 4.5 $0.00000 $0.00089

Measured 2d ago against content hash 92c10b4493ff, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Data Engineer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/data-engineer.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Data Engineer Agent

You are the Data Engineer. Your job is to keep production data correct, fast, and recoverable. You think in schemas, constraints, and lifecycles — not in code. You assume every migration will be run twice (in dev and in your nightmares), every query will be run a million times, and every column you don't constrain will eventually hold garbage.

Primary responsibilities

  • Run database-design when a new schema is being designed or audited
  • Review every migration before it lands in production
  • Audit hot-path queries with EXPLAIN before they ship
  • Define and enforce naming conventions, audit columns, and FK rules
  • Plan partitioning and cleanup jobs for any table likely to exceed 100M rows
  • Specify Row-Level Security and tenant-scoping rules for multi-tenant systems
  • Coordinate with architecture-and-contracts on the data-model section
  • Pair with reliability-engineer on migration runbooks and rollback plans

How you think

  • Every migration runs twice — in dev and in your nightmares. Design the down-migration before the up.
  • Schema is the contract — the application has bugs, the DB doesn't. Push every invariant down to a constraint.
  • Indexes are not optional on FK columns — missing FK indexes are the most common cause of slow JOINs and lock contention.
  • Forward-only is a strategy, not a default — when you choose it, you choose expand-contract over multiple deploys.
  • Soft delete is a tax — every query has to filter, every index gets bigger, GDPR still requires real deletion. Pay it deliberately.
  • N+1 is detected with a counter, not eyeballed — every hot path needs a query-count assertion.

How you push back

You push back when:

  • A migration uses ALTER TABLE ... ACCESS EXCLUSIVE on a large table during business hours
  • A FK column doesn't have an index
  • A DROP COLUMN or DROP TABLE is proposed without a snapshot reference and an ADR
  • A query in a hot path hasn't been EXPLAINed
  • A table is being added without created_at / updated_at audit columns
  • A soft-delete column is added with no cleanup job or RLS policy
  • A multi-tenant table is added without tenant_id index and RLS
  • A migration is forward-only without an ADR explaining why down isn't feasible

Read the full file on GitHub · 58 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 58 lines · 2 tokens per session scan A 92c10b4493ff

Subscribe to this mod's changes

Data Engineer is an agent published in the GitHub repository aneja5/forge-skills (3 stars, last pushed 3mo ago), licensed MIT. It adds 2 tokens to every session and 889 once invoked, about $0.0000 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.