FTP vs SFTP: why plain FTP has no place in modern banking
Both move files. Only one encrypts what travels —credentials included—; and SFTP is not "secure FTP".
Fundamentals
How things actually work — without the hand-waving.
The building blocks of engineering —protocols, encryption, networks, integration and banking— explained with precision and the judgment of someone who runs mission-critical platforms. A maintained knowledge system, not a collection of posts.
Start here What happens when you type a URL and hit Enter?
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PATHS
Learning paths
3
Path · Fundamental · 6 documents
How a secure web request works
Follow the complete journey from entering a URL to receiving a secure application response.
Open the path → Path · Intermediate · 5 documentsEnterprise and banking integration
Understand how enterprise systems connect and why banking integration requires additional controls.
Open the path → Path · Fundamental · 3 documentsApplied cryptography, no hand-waving
What each primitive actually protects: encryption, hashing and certificates, and where they get confused in production.
Open the path →
NET
Networks & transport
5What happens when you type a URL and hit Enter?
The choreography of systems that runs in under a second: from name to IP, the connection, the request and the render.
DNS: the address book of the internet (and when it lies)
How a name becomes an IP, why a change "takes time to propagate", and what you see —and don't— when DNS fails.
IP, subnets and NAT: how the internet finds you
Public and private addresses, why many devices share a single public IP, and how the network is segmented to isolate what's critical.
TCP vs UDP: delivery control versus lower latency
TCP prioritizes ordering, verification and retransmission. UDP cuts coordination when losing or reordering some data beats waiting.
WEB
Web & protocols
1
SEC
Security & cryptography
3Symmetric and asymmetric encryption: why they're used together
Two families of keys with opposite strengths. Why TLS doesn't pick one, but combines both.
Digital certificates: why your browser trusts a site
What a certificate is, who signs it, and how the chain of trust that holds up the web is built.
Hashing is not encryption: why a password isn't "decrypted"
The most common confusion of all. What a hash is, how it differs from encryption, and why it matters for your passwords.
INT
Integration & messaging
2MQ vs Kafka: queues and streams, and when to use each
Queues that distribute work and logs that retain and replay events. Why IBM MQ and Kafka get compared so often yet optimize for different models.
EDI: how companies exchange documents without humans
The family of standards that moves orders and invoices from one ERP to another with no one typing. Older than APIs, and still moving global trade.
FIN
Banking & payments
2SWIFT: how an international transfer actually travels
SWIFT doesn't move money: it moves the instruction. How correspondent banking does the rest, and why it's slow and costly.
ISO 20022: the world's new financial language
The standard now replacing SWIFT's MT messages: rich, structured data for payments. The global migration underway right now.
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