Backend Development
The infrastructure that makes AI-powered systems reliable
What this means
in practice
Backend development in 2026 has the same fundamentals as always — reliability, maintainability, performance under load — plus a new category of infrastructure that AI workloads introduce. Postgres now has a vector column. Your API now streams. Your background jobs now run embedding pipelines. The backend engineer who only knows traditional patterns is leaving performance and reliability on the table.
Go has become the dominant choice for AI infrastructure backend work — not because of any AI-specific feature but because its concurrency model handles the streaming, the parallel embedding jobs, and the inference proxy patterns cleanly. Node.js with NestJS remains the right choice for most application backends where developer velocity matters more than raw throughput. We use both, and we know when to choose which.
What Changed in Backend Development
Backend fundamentals have not changed: reliability, maintainability, performance under load. What has changed is the infrastructure a modern backend needs to support. Any application with AI features needs vector storage, embedding pipelines, streaming endpoints, and often an inference proxy. These are not exotic requirements — they are the new baseline.
The teams that treat AI infrastructure as an afterthought end up with embedding logic in API handlers (blocking, slow), vector queries without indexes (slow at scale), and LLM API calls without fallback (single point of failure). These are solvable engineering problems, and solving them at design time is much cheaper than fixing them in production.
The Database Changed Too
Postgres is still the right database for most applications. What has changed is that a Postgres schema in 2026 typically includes vector columns alongside the traditional relational schema. pgvector provides IVFFlat and HNSW indexes for approximate nearest-neighbor search on embedding vectors. For applications with under ten million vectors and standard accuracy requirements, this is the entire vector infrastructure story — no separate vector database, no new operational complexity.
The pattern: add a vector column (embedding VECTOR(1536)) to the document or content table, generate embeddings in a background job when content is created or updated, query by cosine similarity for semantic search. The similarity query lives alongside your regular SQL queries. Your existing Postgres expertise applies.
Go and the AI Infrastructure Backend
Go has become the language of choice for AI infrastructure components in 2026 — not because of any AI-specific feature, but because of its concurrency model and performance characteristics. Building an inference proxy that handles hundreds of concurrent streaming requests, each maintaining an open SSE connection, is a natural fit for Go's goroutine model. The same proxy in Node.js works but requires more careful backpressure management and is more sensitive to event loop blocking.
Node.js with NestJS remains the right choice for application backends where you are building CRUD APIs, managing business logic, and integrating with a broad ecosystem of npm packages. The two languages are complements, not competitors, and most production AI systems use both.
- Vector schema: pgvector columns on content tables, HNSW index for query performance
- Embedding pipeline: BullMQ job queue for async generation, idempotent on retry
- Streaming layer: SSE endpoints with proper flush configuration and timeout handling
- Inference proxy: routing, caching, fallback, and cost tracking across LLM providers
- Observability: OpenTelemetry traces, Prometheus metrics, structured JSON logs
- Migration discipline: every schema change as a versioned, reversible migration file
What is included
Our process
Architecture Design
Design the service topology, data model, and API surface before writing code. For AI-era applications this includes the vector schema, the embedding pipeline design, and the streaming layer. Decisions made at this stage determine the maintainability of the system for years.
Data Model
Design the database schema with the full data lifecycle in mind: creation, retrieval patterns, update frequency, archival, and deletion. For applications with AI components, add vector columns from the start rather than retrofitting them later.
Core API Implementation
Build the primary API endpoints with proper input validation, error handling, and response schemas. Every endpoint gets Zod or equivalent validation on input, structured error responses, and OpenAPI documentation generated from the code.
Background Infrastructure
Implement the job queue for async processing — embedding generation, email sending, report generation, AI enrichment pipelines. BullMQ with Redis is the standard for Node.js. Go applications use worker pools with channel-based distribution.
Integration Layer
Build the integration points with third-party services — payment processors, AI APIs, external data sources. Each integration gets a circuit breaker, retry logic, and a fallback strategy that does not propagate failures upstream.
Performance and Observability
Profile the hot paths, set up query analysis, configure connection pooling. Instrument with OpenTelemetry for distributed tracing, Prometheus for metrics, structured logging for debug. Observability is not optional — it is how you know the system is working.
Tools and infrastructure we use for this capability.
Why Fordel
We Know the AI Tax on Backend Systems
Vector columns in Postgres, embedding pipelines in job queues, streaming APIs for LLM output, inference proxy layers for cost and fallback management — these are the new backend infrastructure requirements that AI applications introduce. We design for them from the start.
Go for Infrastructure, Node for Application
We match the language to the workload. Go's concurrency model is genuinely better for high-throughput streaming servers and embedding pipelines. NestJS is genuinely better for application backends where developer velocity and ecosystem richness matter more than raw performance. We make the right call for your specific system.
Database Design Is Where Maintainability Is Won or Lost
A well-designed data model with proper indexes, query patterns, and migration discipline survives years of feature additions. A poorly designed one requires increasingly painful workarounds within months. We invest in data model quality upfront.
Observability Is a Non-Negotiable Deliverable
We do not ship backend systems without structured logging, distributed traces, and metric dashboards. When something breaks at 2am, the on-call engineer needs to be able to diagnose the problem from observability data, not from reading code.
Frequently asked
questions
When should we use Go versus Node.js for a backend?
Go for: inference proxies and streaming servers where you need high concurrency and low memory overhead, embedding pipelines that process large volumes of documents in parallel, CLI tools and infrastructure-adjacent services. Node.js with NestJS for: application backends where developer velocity matters, teams coming from a JavaScript-heavy stack, services that lean heavily on npm ecosystem tooling. Most projects end up with Node.js for the application layer and Go for any high-throughput infrastructure components.
What does "the AI tax" on backend systems mean?
Every application that uses AI adds new infrastructure requirements to the backend: vector columns in the database for semantic search, background jobs for embedding generation and indexing, streaming endpoints for LLM output, and often an inference proxy layer for routing between models, managing costs, and handling fallbacks. These are not optional additions — they are the baseline for AI-powered features. Ignoring them leads to systems that technically work but have no observability, no cost control, and no reliability under load.
How do you handle streaming LLM responses from the backend?
Server-Sent Events is the standard pattern. The backend endpoint connects to the LLM API (which streams token-by-token), transforms the stream, and forwards it to the client via SSE. In Go this uses goroutines and channels. In Node.js this uses async iterators or Readable streams. The critical details are: proper flush behavior so tokens reach the client without buffering, connection timeout configuration so long responses do not get cut off, and error handling for mid-stream failures.
How do you manage database migrations in production?
We use migration-based schema management (Prisma Migrate, Flyway, or golang-migrate depending on the stack) with every schema change captured as a versioned migration file. Migrations are applied in CI before deployment — the new code never runs against the old schema. Destructive operations (column drops, table renames) are always done in two phases: a migration that makes the old thing optional, a deployment, and then a cleanup migration. Never drop a column in the same deployment that stops using it.
What is an inference proxy and do we need one?
An inference proxy is a service layer between your application and LLM APIs that handles routing (send this request to GPT-4o, that one to Haiku for cost reasons), caching (return the cached response if we have recently answered this exact question), fallback (if OpenAI is down, route to Anthropic), and cost accounting (track spend by feature, user, or team). If you have more than one LLM-powered feature in your application, an inference proxy layer pays for itself in operational clarity within months.
Ready to work with us?
Tell us what you are building. We will scope it, price it honestly, and give you a clear plan.
Start a ConversationFree 30-minute scoping call. No obligation.