Forem: Eleftheria Batsou

5 APIs I’d use to build data-driven apps: • IPstack IP & location data • Aviationstack Flight & aviation data • Zenserp Search engine results • Marketstack Stock market data • Numverify Phone validation & metadata More info on the article :)

Eleftheria Batsou — Wed, 25 Feb 2026 16:02:37 +0000

Eleftheria Batsou

Feb 25

5 APIs I’d Use to Build Data-Driven Apps in 2026

#api #geolocation

Comments 3

6 min read

5 APIs I’d Use to Build Data-Driven Apps in 2026

Eleftheria Batsou — Wed, 25 Feb 2026 13:22:50 +0000

Introduction

As developers, we don’t need more APIs, we need reliable ones that solve boring but critical problems so we can focus on building actual features. Am I right?

When I’m working on data-driven apps, dashboards, automation tools, or even AI-assisted workflows, I usually look for APIs that:

Are easy to integrate
Return predictable, structured data
Can be composed into larger systems (cron jobs, agents, pipelines)
Don’t require me to maintain my own fragile scrapers or datasets

In this article, I’ll walk through 5 APIs I’d personally use in real projects in 2026, why they’re useful, and how they fit into modern developer workflows.

No marketing talk, just practical use cases, example calls, and realistic outputs. 👇

1. IPstack: Real-time IP Geolocation API Service

The problem it solves:

At some point, almost every app needs location context:

Personalizing content
Detecting suspicious logins
Understanding where traffic comes from
Adjusting pricing, language, or UX

Doing this yourself quickly turns into:

Maintaining outdated IP databases
Handling edge cases (VPNs, mobile carriers, IPv6)
Constant updates you didn’t plan for

This is where IPstack fits nicely. 😊

It gives you accurate IP geolocation data via a simple HTTP API, no infrastructure to maintain, no data scraping.

Example API call (JavaScript)

const ip = '134.201.250.155';
const accessKey = process.env.IPSTACK_API_KEY;

const response = await fetch(
  `http://api.ipstack.com/${ip}?access_key=${accessKey}`
);

const data = await response.json();
console.log(data);

Sample response:

{
  "ip": "134.201.250.155",
  "continent_name": "North America",
  "country_name": "United States",
  "region_name": "California",
  "city": "Los Angeles",
  "zip": "90013",
  "latitude": 34.0453,
  "longitude": -118.2413,
  "connection": {
    "isp": "AT&T Services Inc"
  }
}

Practical use cases

1. Security & anomaly detection
If a user usually logs in from one country and suddenly appears somewhere else, that’s a signal. Not a hard block, just a data point.

2. Smarter analytics
Instead of raw IPs, you get:

Country
City
ISP Which makes dashboards instantly more useful.

3. AI prompt enrichment (lightweight)
If you’re using LLMs:

Inject location context into prompts
Adjust tone, language, or examples automatically

Get started with IPstack API | Documentation | Playground

2. Aviationstack: Real-time Flight Status & Global Aviation Data Without Scraping

The problem it solves:

Flight data is surprisingly useful, even outside travel apps. But collecting it yourself is painful:

Multiple airline sources
Rate limits
Inconsistent formats
Constant changes

Aviationstack centralizes all of this:

Live flight status
Historical data
Airport and airline metadata

And it does it in a way that’s actually developer-friendly. ✈️

Example API call (JavaScript)

const accessKey = process.env.AVIATIONSTACK_API_KEY;

const response = await fetch(
  `http://api.aviationstack.com/v1/flights?access_key=${accessKey}&flight_status=active`
);

const data = await response.json();
console.log(data.data[0]);

Sample response:

{
  "flight_date": "2026-03-18",
  "flight_status": "active",
  "departure": {
    "airport": "Heathrow",
    "iata": "LHR",
    "scheduled": "2026-03-18T10:15:00+00:00"
  },
  "arrival": {
    "airport": "JFK International",
    "iata": "JFK",
    "scheduled": "2026-03-18T13:20:00-05:00"
  },
  "airline": {
    "name": "British Airways"
  },
  "flight": {
    "iata": "BA117"
  }
}

Practical use cases

1. Travel dashboards
If you’re building: internal tools, travel analytics, customer-facing flight trackers, etc. → This API saves weeks of work.

2. Automation workflows
Think:

Cron jobs checking delayed flights
Triggering notifications or refunds
Syncing flight data into internal systems

3. AI-assisted support tools
Instead of asking users for flight details:

Detect flights automatically
Feed structured data into support bots
Reduce back-and-forth

This is a great example of APIs making AI more reliable, not more complex!

Get started with Aviationstack API | Documentation | Playground

3. Zenserp: Fast, Accurate Search Data Built for Developers

The problem it solves

Search engine data is incredibly valuable:

Market research
SEO tools
Competitor tracking
Content analysis

But scraping Google yourself is:

Fragile
Legally questionable
Constantly breaking

Zenserp gives you clean, structured SERP data via an API.

Example API call (JavaScript)

const accessKey = process.env.ZENSERP_API_KEY;

const response = await fetch(
  `https://app.zenserp.com/api/v2/search?q=best+javascript+frameworks&location=United+States`,
  {
    headers: {
      apikey: accessKey
    }
  }
);

const data = await response.json();
console.log(data.organic[0]);

Sample response:

{
  "title": "Top JavaScript Frameworks in 2026",
  "url": "https://example.com/js-frameworks",
  "description": "A comparison of the most popular JavaScript frameworks.",
  "position": 1
}

Practical use cases

1. SEO & content tooling
Build tools that: track rankings, analyze competitors, discover content gaps

2. Market research automation
Instead of manual searches:

Query SERPs programmatically
Store results over time
Detect trends automatically

3. AI + search grounding
If you’re using LLMs:

Ground answers in real search results
Avoid hallucinations
Combine SERP data with summarization

Zenserp works especially well as a data source, not as a finished product. 👨‍💻

Get started with Zenserp API | Documentation | Playground

4. Marketstack: Real-Time & Historical Market Data

The problem it solves:

Financial and market data is one of those things that sounds simple until you try to implement them.

If you’ve ever needed:

Stock prices
Historical trends
End-of-day data
Market analytics for dashboards

You quickly realize you’re dealing with: multiple exchanges, inconsistent data formats, rate limits and delayed updates.

Marketstack gives you a clean, unified API for real-time, intraday, and historical market data, without forcing you to become a finance-data engineer.

Example API call (JavaScript)

const accessKey = process.env.MARKETSTACK_API_KEY;

const response = await fetch(
  `http://api.marketstack.com/v1/eod?access_key=${accessKey}&symbols=AAPL,MSFT`
);

const data = await response.json();
console.log(data.data[0]);

Sample response:

{
  "symbol": "AAPL",
  "date": "2026-03-15T00:00:00+0000",
  "open": 182.45,
  "high": 185.12,
  "low": 181.90,
  "close": 184.67,
  "volume": 73482900
}

Practical use cases

1. Financial dashboards

Perfect for:

Internal analytics tools
Startup KPIs
Investor-facing dashboards You get structured data that’s easy to chart and compare over time.

2. Automation & alerts

Combine Marketstack with cron jobs:

Trigger alerts when prices cross thresholds
Generate daily or weekly reports automatically

3. AI-assisted insights (without hype)

Instead of asking an LLM to “analyze stocks” blindly: feed it real historical data or let it summarize trends, volatility, or anomalies.

APIs like this make AI outputs far more grounded and useful.

Get started with Marketstack API | Documentation | Playground

5. Numverify: Phone Number Validation

The problem it solves:

Phone numbers look simple, but validating them properly is not.

Common issues:

Invalid formats
Wrong country codes
Fake or unreachable numbers
Users typing random values just to bypass forms

Numverify solves this by giving you real-time phone number validation and metadata through a simple API.

Example API call (JavaScript)

const accessKey = process.env.NUMVERIFY_API_KEY;
const number = '+14158586273';

const response = await fetch(
  `http://apilayer.net/api/validate?access_key=${accessKey}&number=${number}`
);

const data = await response.json();
console.log(data);

Sample response:

{
  "valid": true,
  "number": "14158586273",
  "local_format": "4158586273",
  "international_format": "+14158586273",
  "country_name": "United States",
  "location": "California",
  "carrier": "AT&T",
  "line_type": "mobile"
}

Practical use cases

1. Better onboarding flows

Instead of accepting garbage input: validate numbers instantly, reduce failed SMS or WhatsApp deliveries and improve user data quality.

2. Fraud prevention signals

Phone metadata can be combined with: IP location (IPstack) and login behavior. Not as a blocker, but as a risk signal.

3. Automation & CRM enrichment

Automatically enrich leads with:

Country
Carrier
Line type This is especially useful in sales tools and internal CRMs.

Get started with Numverify API | Documentation | Playground

Conclusion

If you’re building data-driven apps in 2026, the real challenge isn’t writing code, it’s getting reliable data without having trouble maintaining it.

The 5 APIs I covered: IPstack for location intelligence, Aviationstack for structured flight data, Zenserp for clean search engine results, Marketstack for financial and market data without custom pipelines and Numverify for phone number validation you can actually trust.

All solve very real problems and fit naturally into modern workflows: dashboards, automation, internal tools, AI-assisted systems,etc.

As always, the best APIs are the ones you barely think about, because they just work. 🚀

Debugging runtime bugs in React/Next.js apps can be frustrating when there's no crash or log to guide you. In this walkthrough, I use theORQL (an AI runtime debugger) to fix 5 common bugs in a weather demo app – from render crashes to silent UI failures.

Eleftheria Batsou — Mon, 12 Jan 2026 12:47:18 +0000

Eleftheria Batsou

Jan 12

Debugging 5 Real-World Bugs: A Practical Walkthrough That Doesn't Include Console.log!

#ai #debug #debugging #frontend

Comments 4

5 min read

Debugging 5 Real-World Bugs: A Practical Walkthrough That Doesn't Include Console.log!

Eleftheria Batsou — Mon, 12 Jan 2026 12:45:58 +0000

As a front-end developer, I deal with bugs all the time. Those sneaky ones that pop up in runtime and mess with my flow or those silent ones that I can never understand what's wrong, are my worst nightmare, or to better phrase, it used to be... Today I want to present you with a solution.

Recently, I collaborated with theORQL team to try their AI runtime debugger. I met the founder, and we had a lovely chat as well as a practical demo of the product. (More info here.)

Eleftheria Batsou

Dec 25 '25

In the era of AI, how do you debug? Here's a Practical Video Guide With Tips From The Founder)

#aidebugging #ai #theorql #aifix

Comments 11

3 min read

It's a tool that lets you debug right in Chrome and sync fixes back to VS Code, making it easier to spot and resolve issues without jumping between tabs or losing context.

In this article, I'm breaking down 5 bugs from a weather app demo. Each one shows what the bug looks like, how it breaks things, and how theORQL helps fix it. I based this on a weather demo repo. I'll link short clips from my YouTube video where I walk through each one, feel free to watch the full thing here for the step-by-step guidance.

If you're tired of manual debugging headaches, give theORQL a look. Let's dive in.