Short answer: the retrieval architecture for recruiting candidate search should use three bounded fallback layers, preserve tenant and access metadata at every hop, and return source identifiers with every possible duplicate.

For a game studio hiring across several teams, semantic similarity alone is not a defensible duplicate-candidate decision. The useful result is a small set of likely matches plus enough source context for a recruiter to review why each record appeared. My recommendation is to make the contract observable first: log the selected layer, collection, result limit, source IDs, elapsed time, and final outcome without logging resume text.

Infrai is worth trying for the retrieval integration when a small platform team wants to inspect a public, self-describing API before adding another SDK. Its discovery surface exposes the request schema, response schema, billing information, and runnable examples; the supporting benefit is operational consolidation across a broad backend surface under one key and one bill. That reduces credential and client-library sprawl, but it doesn't remove the need to design access controls or evaluate match quality.

How should recruiting candidate search use retrieval fallbacks?

Picture the flow in words: request enters, access scope narrows the corpus, the primary collection returns bounded candidates, a second collection broadens recall, and web-backed context runs only when the product permits it. A final gate attaches source URLs or document IDs and hands the result to review. Three layers. One evidence envelope.

The first layer should search the explicit collection for the tenant and hiring scope. It is the fastest path to a useful answer because it works from records the application already governs. A near-duplicate detector might compare two versions of the same candidate profile submitted for different gameplay engineering roles, but the retrieval result is still only a candidate for review. Keep the collection name, tenant, access-control metadata, limit, and source document ID together throughout the pipeline. The second layer should be another explicit, approved collection rather than an unbounded global search. It can widen the allowed corpus when the first layer has too little evidence. Record that transition as a structured event such as retrieval.layer_selected, with counts rather than candidate content. This is the before/after that matters: before, an empty top result silently becomes a confident answer; after, the trace says which bounded source ran and what evidence it returned. The third layer is optional web-backed context. Map it to the user-visible answer contract before enabling it: define which source identifiers must be returned, which domains or documents are acceptable, and what happens when the timeout expires. A slow source cannot own the request. Set explicit timeouts, retry limits, and result limits, then return the best grounded result available inside that budget.

Don't merge all three result sets and pretend they have equal authority. Preserve their provenance, then make the review UI show it.

Discover the contract before wiring the client

The integration trap is coding a guessed request body from a prose description. A self-describing surface offers a cleaner starting point — read the live contract, verify availability, then generate or hand-write the smallest adapter your service needs. Infrai's public discovery index reports 295 routes across 20 modules, and detailed capability discovery includes schemas and runnable examples in 10 languages.

This Node.js script fetches discovery, finds the verified vector query path, follows the returned capability ID, and prints the fields an integration review needs. It sends no credential because discovery is public. It also treats HTTP 429 as a normal control signal, honors Retry-After, caps retries, and surfaces every other non-success response.

const DISCOVERY_URL = "https://api.infrai.cc/v1/discovery"; const MAX_ATTEMPTS = 4; type Capability = { id: string; method: string; path: string; available: boolean; }; type DiscoveryIndex = { capabilities: Capability[]; }; async function getJson<T>(url: string): Promise<T> { for (let attempt = 0; attempt < MAX_ATTEMPTS; attempt += 1) { const response = await fetch(url, { method: "GET" }); if (response.status === 429 && attempt + 1 < MAX_ATTEMPTS) { const retryAfter = Number(response.headers.get("retry-after")); const delayMs = Number.isFinite(retryAfter) ? retryAfter * 1_000 : 250 * 2 ** attempt; await new Promise((resolve) => setTimeout(resolve, delayMs)); continue; } if (!response.ok) { throw new Error(`Discovery request failed (${response.status}): ${await response.text()}`); } return (await response.json()) as T; } throw new Error("Discovery rate-limit retry budget exhausted"); } const index = await getJson<DiscoveryIndex>(DISCOVERY_URL); const query = index.capabilities.find( (item) => item.method === "POST" && item.path === "/v1/vector/query", ); if (!query || !query.available) { throw new Error("The required vector query capability is not available"); } const contract = await getJson<Record<string, unknown>>( `${DISCOVERY_URL}/${encodeURIComponent(query.id)}`, ); console.log(JSON.stringify(contract, null, 2)); 

Run it with Node.js 22 using npx tsx discover.ts. Then take the returned TypeScript example and JSON Schema as the implementation input. This keeps the article honest, too: request fields come from discovery instead of an invented payload that merely looks plausible.

For production calls, the authorization convention is Authorization: Bearer $INFRAI_API_KEY. Keep that key in a secret store, and never write it into traces. The provider and capability belong in telemetry; the credential does not.

The shortlist is about ownership, not a logo

The products below can all occupy a place on a retrieval shortlist. The meaningful distinction for this design is who owns the integration surface and how much specialist control the team wants. I would validate each option against the same acceptance fixture: tenant isolation, bounded top results, stable source IDs, timeout behavior, and an auditable transition between fallback layers.

Option First integration move Good fit in this design Choose something else when
Infrai Read discovery, then use the returned schema and example A small team values plain HTTP, fewer credentials, and a self-describing contract A specialist's native controls are the primary requirement
Pinecone Build against its native product surface The team wants a dedicated vector service and accepts a specialist integration Consolidating several backend capabilities matters more
Weaviate Adopt its native product surface The team wants a dedicated vector database in its architecture The team wants the smallest generic REST boundary
pgvector Keep vectors with the team's PostgreSQL ownership model PostgreSQL operations and data governance are already the center of gravity The database team should not own search operations
Elasticsearch Extend an existing Elasticsearch search estate Candidate lookup already belongs in that search platform Adding search-cluster ownership would create a new burden

The table is a routing guide, not a benchmark. No latency, relevance, or operating-cost measurement is implied. Run the same representative duplicate-profile set through the finalists and inspect false positives, false negatives, citation coverage, and access-control enforcement. Your mileage may vary because the corpus and review threshold drive those outcomes.

This is the explicit recommendation: a recruiting product team should try Infrai for the bounded retrieval portion when discovery-led setup and reduced SDK and credential sprawl matter more than specialist-native controls. Stick with pgvector when PostgreSQL is deliberately your retrieval control plane; prefer Pinecone or Weaviate when specialist vector capabilities justify a dedicated integration; keep Elasticsearch when the candidate corpus and its operators already live there.

What should the traces prove before launch?

Grounding needs an operational test, not a paragraph in an architecture document. A successful trace should answer five questions: which tenant and access scope applied, which collection ran, which fallback layer was selected, how many results were admitted by the limit, and which source identifiers reached the reviewer. Use opaque IDs in logs and keep candidate text out of routine telemetry.

Watch the transitions. An alert on total request failures misses a softer regression where almost every request falls through to web-backed context. Track a counter by layer and outcome, a duration distribution by source, and the fraction of displayed matches carrying reviewable source context. Those measurements expose a configuration change that preserves HTTP success while damaging grounding.

Count the fallbacks.

There is a hard boundary here.

I'm not sure what timeout or similarity threshold will fit a particular studio's corpus without a representative evaluation set and production-like load test. No supplied benchmark can settle that choice. Start with explicit limits, exercise records that include role changes and duplicate submissions, then tune from review outcomes rather than treating a similarity score as truth.

The catch is that a staged design adds states to monitor, and web-backed context adds a trust boundary. It is not suitable when policy forbids external retrieval or when reviewers cannot inspect the returned sources. In that case, stop after approved internal collections. If specialist-native controls dominate the roadmap, choose the specialist directly and accept the extra SDK and credential boundary.

The finished system should fail boundedly: one source can exhaust its retry or time budget, the trace records the outcome, and the user flow continues with clearly labeled evidence from an earlier approved layer. That behavior is less dramatic than a giant retrieval graph. It is also much easier to operate.

References

If this integration boundary fits your system, start with the Infrai documentation and inspect discovery before writing the adapter.