What does Boolean search mean in recruitment?
Boolean search means you describe the candidate you want as a logical formula instead of a loose set of words. The name comes from George Boole, the mathematician behind the true/false logic that search engines still use. A plain search for "java developer amsterdam" leaves it to the search engine to guess what matters. A Boolean string tells it: the title must be one of these variants, this skill must appear, these profiles must be left out.
For recruiters, that precision decides whether a search returns 40 useful profiles or 4,000 mixed ones. It also makes a search repeatable: a colleague can run the same string next month and understand why each result appeared. That is why Boolean search is still part of almost every sourcing training, even as more of the searching itself is done by software.
Where you can use a Boolean string
Most tools recruiters touch accept at least part of the syntax: LinkedIn search and LinkedIn Recruiter, job boards and CV databases, many applicant tracking systems and CRMs, and Google or Bing for X-ray searches. The details differ per tool, so a string that works in one place can silently fail in another. The sections below cover the rules per platform.
Which Boolean operators should every recruiter know?
Five building blocks cover nearly every search. Write operators in capitals: several platforms, LinkedIn included, only recognise them that way.
Wildcards (an asterisk to catch develop, developer and development at once) work in some job boards and ATS searches, but LinkedIn states it does not support them. Check each tool before relying on a wildcard.
How do you build a Boolean search string step by step?
Start from the vacancy, not from the operators. A good string is a translation of three questions: what is this person called, what can they demonstrably do, and who do you not want to see. Everything else is filtering you can often do better with location, industry or seniority filters in the tool itself.
- 1. List the title variants. Collect every name the role goes by, including older titles and the local language: ("software engineer" OR "software developer" OR "backend developer" OR ontwikkelaar).
- 2. Add one or two must-have skills with AND. Pick the requirements that truly disqualify, not the whole wish list: AND (Python OR Django).
- 3. Remove predictable noise with NOT. Recruiters, students and vendors often mention the same keywords: NOT (recruiter OR "talent acquisition" OR intern).
- 4. Test and read the first 20 results. If more than a few are wrong, find the word that let them in and adjust.
- 5. Save the string with a note. Write down what you excluded and why, so the next search on a similar vacancy starts from something that worked.
Why brackets matter more than people think
Without brackets, a string like "Java OR Kotlin AND Android" is read in the order the platform chooses. LinkedIn documents its order of precedence: quoted phrases first, then parentheses, then NOT, then AND, then OR. That means an unbracketed OR is evaluated last and can pull in every Java profile, Android or not. Writing "(Java OR Kotlin) AND Android" removes the ambiguity everywhere.
What does LinkedIn support, in free search and in Recruiter?
Both LinkedIn's free search and LinkedIn Recruiter accept AND, OR, NOT, quotation marks and parentheses, but they handle them differently. According to LinkedIn Help, the free search bar on LinkedIn.com accepts a Boolean string directly; operators must be in capitals, and braces, square brackets, angle brackets and asterisk wildcards are not supported. Plus and minus signs are not officially supported either. Stop words such as "by", "in" and "with" are ignored.
In Recruiter and Recruiter Lite, Boolean works in more places. LinkedIn lists job titles, location, companies, skills and assessments, schools, industries and spoken languages as filters that are treated as Boolean, with keywords and projects supporting modifiers as well. LinkedIn also warns that too many facets in one Boolean query can cause problems and recommends moving long strings into the individual filters. In practice: put titles in the title filter, companies in the company filter, and keep the keyword field for skills and exclusions.
Practical LinkedIn rules that save time
Write NOT, AND and OR in capitals. Use straight quotation marks, not the curly ones that phones and word processors insert. Do not rely on the asterisk. Test a long string by removing one block at a time: if the result count jumps, that block was doing the filtering. If you are weighing whether a Recruiter seat is worth it for this kind of searching, our guide on LinkedIn Recruiter cost sets out what you pay for.
What is X-ray search and how do you run one on Google?
X-ray search uses a web search engine to look inside one website, usually LinkedIn, GitHub or a professional register. You combine Boolean logic with the site: operator so Google only returns pages from that domain. Google's own help documents site:, exact-match quotes, the minus sign for exclusion and filetype:, and notes that there must be no space between the operator and the term.
X-ray is useful when you have no Recruiter seat, when you want to search public profiles on sites without a good internal search, or when you look for CVs and portfolios published as files. It has limits: you only see what the search engine has indexed, results are not complete, and snippets can be outdated. Treat X-ray as a way to discover names and signals, then check the live profile.
- LinkedIn profiles: site:linkedin.com/in ("data engineer" OR "analytics engineer") (Utrecht OR Amersfoort) -recruiter
- GitHub users: site:github.com "Rotterdam" (Rust OR Go) "followers"
- CVs as documents: (cv OR resume OR "curriculum vitae") "process engineer" filetype:pdf -template
- Conference speakers: ("speaker" OR "spreker") "platform engineering" 2026 site:nl
A note on OR and the minus sign in Google
Google's operator page lists the minus sign for exclusion, not the word NOT, so use "-recruiter" rather than "NOT recruiter" in X-ray strings. OR in capitals is widely used in X-ray searches but is not on that page, so check whether your results actually broaden. Collecting profiles in bulk from search results raises both platform terms and privacy questions; our guide to GDPR and candidate sourcing explains what to keep in mind.
Which Boolean search strings work for common roles?
Use these as starting points and adapt titles to your market and language. They are written for a keyword field; in LinkedIn Recruiter, move the title block into the title filter.
Software and data
- Backend developer: ("backend developer" OR "back-end developer" OR "software engineer") AND (Java OR Kotlin) AND (Spring OR microservices) NOT (recruiter OR intern OR student)
- Data engineer: ("data engineer" OR "analytics engineer" OR "big data engineer") AND (Spark OR dbt OR Airflow) AND (SQL OR Python)
- DevOps: (DevOps OR SRE OR "site reliability" OR "platform engineer") AND (Kubernetes OR Terraform) NOT (sales OR "account executive")
Healthcare
- ICU nurse: ("registered nurse" OR "IC-verpleegkundige" OR "intensive care nurse" OR verpleegkundige) AND (ICU OR "intensive care" OR IC) NOT (student OR leerling)
- Physician assistant: ("physician assistant" OR "PA" OR "verpleegkundig specialist") AND (orthopedie OR orthopaedics)
Engineering, technical and trades
- Service engineer: ("service engineer" OR "field engineer" OR "servicemonteur" OR "storingsmonteur") AND (PLC OR hydraulics OR hydrauliek)
- Electrician: (elektricien OR "elektrotechnisch monteur" OR electrician) AND (NEN3140 OR "industriële automatisering")
- Process engineer: ("process engineer" OR procestechnoloog) AND (food OR dairy OR voedingsmiddelen) NOT (student OR stagiair)
Sales, finance and logistics
- SaaS account executive: ("account executive" OR "account manager" OR "new business") AND (SaaS OR software) AND (B2B) NOT (recruitment OR staffing)
- Controller: (controller OR "business controller" OR "financial controller") AND (IFRS OR consolidatie OR consolidation) AND (SAP OR Exact)
- Planner: (planner OR "transport planner" OR "logistiek planner") AND (TMS OR "warehouse management") NOT (event OR wedding)
