AI development: LLM features that ship with an evaluation set, not a demo
WeBuildStack is a remote-first software development company in Bengaluru, India, that builds web and mobile applications and the cloud behind them. For an AI feature inside an existing web or mobile application, grounded in your data with guardrails and an evaluation set: a written quote within 48 hours and an MVP in six weeks with deployment included, with team hours set to your timezone. 15+ engineers, 100+ projects.
Four kinds of feature cover most requests: assistants grounded in your data, document extraction, tool-calling agents and classification. Each is built on hosted models with retrieval, guardrails and an evaluation set, quoted in writing within 48 hours, and live on your own cloud account in six weeks.
We build the whole stack. MVP in 6 weeks, deployment included.
What you get
- Assistants grounded in your documentation and records with retrieval (pgvector or a managed vector store), sources shown with every answer
- Document extraction and classification pipelines with schema-validated outputs and a human review queue
- Tool-calling agents that look up, draft and act inside your product, with permission checks in code and confirmation for writes
- An evaluation set from real questions, run in CI on every prompt, model or retrieval change
- Guardrails: scope, prompt-injection handling, personal-data masking, rate limits and cost caps per conversation
How a typical AI project runs
- Week 1
01Scope and quote
A technical lead reads your brief, asks the awkward questions and sends a written AI quote within 48 hours.
- Weeks 2 to 5
02Build in weekly sprints
A demo every Friday. The tech lead reviews every pull request before it merges, and you can see the repo at any time.
- Week 6
03Launch, deployment included
We deploy to your cloud accounts, hand over the repos and a runbook. You own the code and the IP.
AI app builder, AI development, or both
An AI app builder generates an application from a prompt; AI development adds model-driven features to a product you already run. They solve different problems.
| Kind of partner | Trade-off | Best for |
|---|---|---|
| AI app builders (Lovable, Bolt, v0, Replit Agent) | A working prototype in hours and real code you can export; quality varies and nobody reviews it unless you arrange that. | Testing whether anyone wants a new, simple product. |
| Hosted assistant products and plugins | Quick to switch on; limited grounding in your data, little control over tools, privacy terms set by the vendor. | Generic help on a site with no account data involved. |
| AI development with a studio (where WeBuildStack sits) | Retrieval over your own data, tools behind your authorisation, evaluation and cost control; weeks rather than hours. | A feature inside a product with real users, records and obligations. |
| In-house ML team | Deepest ownership; expensive to assemble and most product features do not need model training at all. | Products whose core advantage is a model you train yourself. |
Where this service fits
- 01
Week one: the job, the data, the evaluation set
One sentence for what the feature does, an inventory of the content it may use and who may see it, and fifty to a few hundred real questions with accepted answers.
- 02
Weeks two to five: retrieval, tools, guardrails
The feature end to end on staging with streaming responses, sources, tool calls behind authorisation, and the evaluation run on every change.
- 03
Week six: rollout with a human path
Internal first, then a cohort, then wider, with cost per conversation and escalation rate measured against the same work done by email or phone.
AI Development: common questions
Something not covered here? Ask a tech lead. We reply within one business day.
Yes, for an AI feature inside an existing web or mobile application, grounded in your data with guardrails and an evaluation set. A written scope and fixed quote within 48 hours, an MVP in six weeks with deployment included, a tech lead reviewing every pull request, and code you own; the team works in your timezone from Bengaluru, India.
Almost never for a first feature. Retrieval over your own content with a hosted model covers most product assistants. Fine-tuning comes later, for style or narrow tasks, once you have evaluation data to measure it against.
Ground every answer in retrieved sources and show them, restrict the job in the system prompt with a refusal path, validate tool arguments in code, and measure groundedness on a fixed evaluation set before and after every change.
Whichever your data-residency and privacy terms allow and your evaluation set prefers: OpenAI, Anthropic, Gemini or open-weight models on your own cloud. The provider sits behind an interface so switching is configuration.
Only what the task needs is sent to the provider, identifiers are masked where possible, retrieval respects the same permissions as the rest of the product, and the processing terms are checked against DPDP, GDPR or HIPAA as your users require.
Proportional to tokens: context size, conversation length and model choice. We instrument cost per conversation from day one, cache the fixed prompt, route simple questions to a smaller model and set budget alerts before launch. Build cost is quoted in writing within 48 hours.
Yes. The feature is a bounded service with an internal API; the rest of your product does not need to change. We have added assistants to React, Angular, Django, Node.js and Java products.
Tell us about your AI project
Two minutes to fill in. A technical lead replies within one business day with questions and suggested next steps; a written, fixed quote follows within 48 hours of a call.
- Reply within one business dayFrom a technical lead, not a sales inbox.
- Written quote in 48 hoursScope, timeline, entry price and what is included.
- Start when you are readyNo retainers or commitments before the quote.
Prefer to talk it through?
Send us a few lines. A technical lead replies with how we would approach it, within one business day.
- We speak in hours, not days
- Written quote within 48 hours
- Deployment included, you own the code