Six disciplines we've refined across every agent we've shipped. Each one survives a model upgrade, a vendor swap, and a year of production traffic.
Eval-driven development
We build a golden set of 200–500 representative inputs per agent — sourced from your real tickets/transcripts/docs, anonymized, and reviewed by your SMEs. Each is scored against a customer-signed rubric (correctness, faithfulness, refusal-when-needed, action-safety, tone). Every PR — prompt, tool, model, retrieval index — runs the full suite. CI blocks merge below 95% pass-rate on the rubric the customer owns.
Right model per turn
A typical agent makes 6–20 model calls per task. We route each turn by reasoning depth, latency SLA, and per-call cost ceiling — Opus / Sonnet 4.x / GPT-5 / Haiku / Gemini Flash in the same workflow, with auto-failover. Router decisions are logged with rationale; you can A/B route policies the same way you A/B prompts.
Approval classes, not approval buttons
Every external write action is classified at design time: auto (read-only / fully reversible), soft-confirm (one-tap, can be undone in 24h), hard-approve (human signature + audit trail), or manual-only (agent prepares, human executes). Mapping is reviewed with your compliance team before a single tool gets wired up.
Every action, replayable
We instrument with OpenTelemetry-compatible tracing (Langfuse / Phoenix / Datadog LLM Observability, your call). Every trace captures the full plan, every tool call with inputs/outputs, the model variant, latency, token cost, and the human override if one happened. A 3-month-old incident replays in 60 seconds. Your team owns the dashboards on day one.
47 ways agents break — we test for all of them
We maintain an internal catalog of agent failure modes (prompt-injection vectors, tool-loop patterns, hallucinated citations, role-leak, refusal-bypass, retrieval-poisoning, cost-runaway, stale-context, etc.). Every system ships with regression tests for every applicable mode, and a quarterly review against new modes that emerge in the field.
Production traces feed evals
Bad traces from production (low-confidence outputs, escalations, customer corrections) are auto-clustered and surfaced weekly. The most informative get added to the golden eval set — with your SME's sign-off — so the system measurably improves and regressions get caught the moment they appear.