API-first
API-first is a product and engineering approach in which APIs are treated as primary, reusable product interfaces from the start rather than added after an application is already built.
Canonical Upseed vocabulary
Startup glossary
Plain definitions for the funding, ownership, program, metric, and ecosystem language you encounter while building or backing a startup.
AI & Technical
5 terms
71 reviewed definitions in the current glossary
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Technical debt
Technical debt is the future cost of choosing a faster, easier, or locally convenient technical approach now instead of a more sustainable approach that would make future change easier.
Technical diligence
Technical diligence is the structured review of a company's technology, engineering practices, architecture, codebase, infrastructure, security, data, technical team, IP, and product-delivery capability before an investment, acquisition, partnership, or major enterprise purchase.
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Every published term requires an Upseed-authored definition, a completed review, high source confidence, and at least one HTTPS source. Each entry links to one primary or representative source and states how many sources were reviewed.
Last reviewed
June 5, 2026
Known limits
Startup and investment language can vary by market, document, and jurisdiction. These definitions explain common usage and are not legal, financial, tax, or investment advice.
Upseed is an independent guide. Definitions are educational explanations, not representations made on behalf of the organizations or sources linked.