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Choosing between Claude, GPT and Gemini for your product

MK Tech Monk2026-03-1210 min read


The most common question we get from product teams starting AI work is "which model should we use?" — usually phrased as if there is a single correct answer that a benchmark will reveal. There isn't. Model choice is an architecture decision shaped by your constraints, and the right answer often changes within a single product.

Here is the framework we use instead of staring at leaderboards.

Start from the task, not the model

The first move is to stop talking about "the model" and enumerate the actual inference tasks in your product. A support assistant might have: an intent classifier, a retrieval re-ranker, a long-context summariser, and a customer-facing answerer. Those have wildly different requirements. Bundling them under one model choice is how teams end up overpaying for classification and underpowering the part customers actually see.

For each task, write down four things: latency tolerance, accuracy bar, context size, and cost sensitivity. Now you have a spec, and model selection becomes an engineering exercise rather than a vibe.

The dimensions that actually decide it

Reasoning depth. For tasks where the model must follow multi-step instructions, hold constraints, and not contradict itself — agentic workflows, careful drafting, code — frontier models earn their cost. This is where Claude tends to shine in our work, particularly on instruction adherence and staying within guardrails over long interactions.

Latency and cost at volume. A classifier running on every inbound message has a budget measured in fractions of a cent and milliseconds. Here a smaller, faster model — often a lighter tier from any of the major providers — beats a frontier model that is more capable than the task requires. Capability you do not need is just latency and cost.

Context window and recall. Long-context tasks (digesting a large document set in one pass) reward models with both a large window and good recall across it. A big window with poor mid-context recall is a trap; test recall, do not trust the spec sheet.

Ecosystem and deployment constraints. If you are committed to a cloud, Bedrock, Azure OpenAI and Vertex AI shape what is realistically available with your compliance and data-residency requirements. The "best" model you cannot deploy under your DPA is not the best model for you.

Multimodality. If you need native image, audio or video understanding, that requirement narrows the field quickly and should be evaluated on your actual inputs, not demos.

Don't marry one provider

The architectural mistake we see most is hard-coding a single provider's SDK throughout the codebase. Models improve and prices move on a timescale of months. Put a thin abstraction between your application and the provider — a single module that speaks your domain's notion of "generate" and "embed" — so that switching a task to a different model is a config change, not a refactor.

This is not over-engineering. We have changed the model behind a production feature three times in a year for cost and quality reasons. Teams without that seam did not; they were trapped by their own integration.

Evaluate on your data, always

Public benchmarks tell you how models do on public benchmarks. They are weakly predictive of how a model does on your support tickets, your legal clauses, your clinical notes. Before committing, build a small evaluation set — fifty to a few hundred real examples with known-good outputs — and run candidates through it. This is a day of work that routinely overturns the "obvious" choice.

Keep that set. It becomes your regression harness when you change models, prompts or retrieval later.

Cost-aware by design

Once tasks are separated, an obvious pattern emerges: route by complexity. Easy inputs go to a cheap fast model; only inputs that need it escalate to a frontier model. Add prompt caching for stable system context and batching where latency allows. We routinely cut AI spend by half or more with routing and caching alone, with no quality loss, because most traffic never needed the expensive path.

A pragmatic default

If you want a starting point rather than a framework: use a strong frontier model (Claude is our frequent default for reasoning-heavy, guardrail-sensitive work) for the customer-facing, correctness-critical path; use a small fast model for classification and routing; keep embeddings with whatever pairs well with your vector store; and put the abstraction seam in from day one so none of this is permanent.

The honest summary: there is no best model, only the best model for a specific task under specific constraints — and the engineering that lets you change your mind cheaply is worth more than getting the first choice perfect.