Blog
Development, infrastructure, SEO, AI and IT for business — short and to the point.
1495 articles
- Databases & data4 min
NULL in SQL: IS NULL, COALESCE and Common Traps
NULL means an unknown value, so any comparison with it gives UNKNOWN instead of true or false; check it with IS NULL, replace it with COALESCE, and forbid it with NOT NULL wherever a value must always exist.
Basics - Hosting & cloud4 min
How to Set Up SPF, DKIM and DMARC for Your Domain
SPF lists the servers allowed to send mail for your domain, DKIM signs every message with a key, and DMARC tells receivers what to do with mail that fails those checks. All three are DNS records, and you verify them by reading the headers of a real message.
Practice - IT careers3 min
From Middle to Senior: What Really Changes in Your Work
A senior engineer owns outcomes, not tasks: they find problems themselves, make technical decisions with the business in mind and make the team stronger. You can demonstrate this level before the promotion by owning an area and documenting your decisions.
Advanced - Tools & no-code4 min
API Authorization in Postman: API Keys, Bearer and OAuth 2.0
Set authorization once at the collection level and let requests inherit it via Inherit auth from parent; keep tokens in environment variables, refresh them with a pre-request script, and store secrets in local values or Vault, never in shared data.
Practice - IT by industry4 min
Law Firm Practice Management Software: What It Does
Practice management software keeps every matter, procedural deadline, document, billable hour and client message in one place, reminds you of due dates and produces invoices, while access rights protect confidential data.
Basics - Networks & office IT4 min
What Is MDM and How Companies Manage Work Laptops and Phones
MDM is a system a company uses to centrally configure, secure and, when needed, wipe work laptops and phones without touching each device by hand.
Basics - IT for business4 min
NDA in IT Projects: What It Protects and What It Doesn't
An NDA protects specific confidential information you share with a contractor, such as data, documents, code and business processes. It barely protects the idea itself, and its strength depends on clear definitions and provable leaks.
Basics - Web development3 min
npm vs Yarn vs pnpm: Which Package Manager to Use
npm is the reliable default, pnpm saves disk space and enforces stricter dependencies, which shines in monorepos, and Yarn suits teams that want its special modes; above all, use one manager and one lockfile per project.
Practice - SEO3 min
Meta Tags for SEO: Which Ones Matter and Which Don't
For SEO, title, meta robots and viewport genuinely matter, description affects snippet click-through, Open Graph controls how links look in social apps and messengers, and Google ignores meta keywords.
Basics - DevOps3 min
No Space Left on Device: How to Free Disk Space on Linux
Check df -h and df -i, find large directories with du or ncdu, clean old logs, Docker leftovers and package caches, then configure logrotate so the problem does not return.
Practice - AI & automation4 min
Hybrid Search and Reranking: Improving RAG Retrieval Quality
Hybrid search combines exact word matching (BM25) with semantic similarity (vectors), a reranker reorders candidates more precisely, and query rewriting rescues poorly phrased questions. Turn each step on only after measuring it on your own test set.
Advanced - Programming3 min
PHP Composer and PSR Standards: Setting Up a Modern Project
A modern PHP project starts with composer.json: Composer installs dependencies and provides PSR-4 autoloading, while PHP-CS-Fixer and PHPStan enforce PSR-12 style and catch bugs before runtime.
Practice - Mobile development3 min
How to Test a Mobile App: Manual, Automated and Device Farms
A reliable setup is many fast unit tests, fewer UI component tests and a handful of end-to-end flows, plus manual checks before release. Emulators are fine for daily development, while real devices and cloud farms verify the app on what your users actually own.
Practice - Marketing & analytics4 min
Meta Conversions API: How to Set It Up and Deduplicate Events
Conversions API sends events to Meta from your server alongside the pixel; to avoid double counting, both sources must send the same event_name and event_id, and good matching needs normalised, SHA-256 hashed customer data.
Advanced - Design & UX4 min
Responsive Design for Designers: Breakpoints and Layouts
Design the mobile version first, set 3-4 breakpoints where your content breaks, define the grid and block behavior for each range, and build frames with auto layout in Figma so developers see rules, not just pictures.
Practice - Telegram & messengers4 min
How to Design a Lead Generation Bot Scenario in Telegram
A good scenario opens with a clear benefit, asks 2-4 questions with buttons, branches on the answers, requests the phone via a Share contact button and immediately sends the manager a lead card with every answer and the source.
Practice - E-commerce & CRM4 min
How to Integrate Payme Into a Website: Developer Guide
Payme calls your server over JSON-RPC: you implement six Merchant API methods, check authorization and the amount in tiyin, store transactions with states 1, 2, -1 and -2, and pass every sandbox scenario before switching to the live key.
Practice - Security4 min
SIM Swap Attacks: How Criminals Steal Your Number and How to Stop It
In a SIM swap, a criminal gets your number re-issued to their SIM and starts receiving your SMS codes. Protect yourself with passwords and cloud passwords where possible, non-SMS second factors and an operator ban on remote re-issue.
Basics - Databases & data4 min
SQL Pagination: OFFSET vs Keyset (Cursor) Pagination
OFFSET forces the database to read and discard every skipped row and drifts when rows are inserted; keyset pagination continues from the last shown record with a WHERE on a stable sort and stays equally fast at any depth.
Practice - Hosting & cloud4 min
What Uptime and SLA Mean: 99.9% vs 99.99% in Practice
99.9% uptime allows up to 43 minutes of downtime a month, 99.99% about 4 minutes. An SLA promises that level, but when it is broken you usually get a credit on your next bill, not compensation for your losses.
Basics - IT careers3 min
Performance Reviews in IT: How to Prepare and Get Promoted
A promotion at performance review is prepared all year, not the week before: you track achievements, agree on next-level criteria with your manager early and arrive with facts rather than feelings. A self-review is evidence of impact, not a list of tasks.
Advanced - Tools & no-code4 min
Automated API Tests in Postman and Newman
In Postman you add JavaScript checks to each request with pm.test, pass data between requests through variables, and run the whole collection from the command line with Newman, including in CI on every commit.
Advanced - IT by industry4 min
CRM for a Learning Center: Leads, Groups and Payments
A learning center CRM should carry each student through the whole journey — lead, trial lesson, group enrollment, attendance, monthly payment and debt reminder — and connect these stages automatically.
Practice - Networks & office IT4 min
What Is Mesh Wi-Fi and When an Office Needs It
Mesh Wi-Fi is a set of nodes that act as one network and pass traffic to each other, ideally over cable; it suits small offices without cabling, while larger or demanding offices are better served by wired, centrally managed access points.
Basics
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