Senior Software Engineer (Dataset)

Bitwarden promotes better internet security and safety with the leading open source password management solution for individuals, teams, and business organizations. Our philosophy on security is that “we are all in this together” – we continue to offer a full-featured free version of Bitwarden so that everyone can be protected with strong password management. We also provide enterprise-grade solutions to some of the largest companies in the world, and will continue to innovate in the identity and authentication market as the world starts to grow beyond passwords. Read more on the Bitwarden blog. 

Autofill Coverage owns the measurement of autofill quality end-to-end: establishing a manual baseline across top sites in every major category, automating that baseline into a repeatable regression and benchmarking suite, and reporting coverage, regressions, and competitive standing on a fixed cadence. As a Senior Software Engineer on the Dataset side of this team, you'll own Map the Web, the curated dataset that establishes ground truth for how real-world login and signup forms are structured. Map the Web is the foundation that Fill Assist is built on, Bitwarden's targeted, rules-based system that resolves autofill issues on specific sites by layering vetted, site-specific field mappings on top of our standard heuristic qualification engine, even for forms that are out of alignment with the official spec. When regression testing (run by your SDET counterparts) surfaces a mapping defect, you own the fix in the dataset; when it surfaces anything else, you own routing it to the right team.

• →Own the ongoing curation, accuracy, and coverage of the Map the Web dataset across top sites in every major login/signup category, including the underlying targeted rules that power Fill Assist.
• →Design and maintain the data model and versioning strategy for site-specific field mappings, including backward-compatibility guarantees across supported browser client versions.
• →Build and maintain tooling and process for validating rule quality and safety before publication since faulty rules currently bypass heuristic fallback entirely.
• →Triage inbound reports of autofill defects (support tickets, regression findings) to determine whether a fix belongs in Map the Web or should be handed off to another team, and own the attributed hand-off when it's the latter.
• →Partner with the Autofill Coverage SDETs to close the loop between automated regression/benchmarking results and dataset updates.
• →Maintain the Map the Web repository (github.com/bitwarden/map-the-web) as a well-documented, contributor-friendly project, including guidance for how the dataset's rules interact with client-side fetching, sync, and storage.
• →Monitor how the dataset scales over time and flag technical debt or maintenance-burden risks early as this is a known failure mode from prior public-rules efforts (e.g. BIT tests, Equivalent Domains) that this team is explicitly designed to avoid repeating.
• →Work closely with the US Autofill team on validation standards.

• Overall Experience: 6-10 years in Software Engineering.
• Web Forms & DOM Expertise: Strong practical knowledge of HTML form structure, CSS selectors, and the ways real-world login/signup pages diverge from spec (nonstandard field identifiers, dynamically rendered forms, hidden/irrelevant fields).
• Dataset/Data Pipeline Experience: Experience building and maintaining a structured, versioned dataset at scale to keep a large, evolving corpus accurate over time.
• Technical Stack: Proficiency in TypeScript; familiarity with browser extension architecture (state/storage services, sync mechanisms) is a plus given this dataset feeds directly into browser client behavior.
• Quality & Validation Mindset: Experience designing automated or semi-automated grading/validation systems to catch bad data before it ships, rather than relying on manual review alone.
• Security Awareness: Basic understanding of the security posture differences between vetted, human-authored rules and heuristic-based autofill.
• Open Source & Communication: Excellent written communication and a strong passion for open-source software, developer tooling, and modern internet security.

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